/*
 * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.tools.javac.parser;

import com.sun.tools.javac.util.Name;
import com.sun.tools.javac.util.Position.LineMap;

/**
 * The lexical analyzer maps an input stream consisting of ASCII characters and
 * Unicode escapes into a token sequence.
 * 
 * <p>
 * <b>This is NOT part of any supported API. If you write code that depends on
 * this, you do so at your own risk. This code and its internal interfaces are
 * subject to change or deletion without notice.</b>
 */
public interface Lexer {

	/**
	 * Has a @deprecated been encountered in last doc comment? This needs to be
	 * reset by client with resetDeprecatedFlag.
	 */
	boolean deprecatedFlag();

	void resetDeprecatedFlag();

	/**
	 * Returns the documentation string of the current token.
	 */
	String docComment();

	/**
	 * Return the last character position of the current token.
	 */
	int endPos();

	/**
	 * Return the position where a lexical error occurred;
	 */
	int errPos();

	/**
	 * Set the position where a lexical error occurred;
	 */
	void errPos(int pos);

	/**
	 * Build a map for translating between line numbers and positions in the
	 * input.
	 * 
	 * @return a LineMap
	 */
	LineMap getLineMap();

	/**
	 * Returns a copy of the input buffer, up to its inputLength. Unicode escape
	 * sequences are not translated.
	 */
	char[] getRawCharacters();

	/**
	 * Returns a copy of a character array subset of the input buffer. The
	 * returned array begins at the <code>beginIndex</code> and extends to the
	 * character at index <code>endIndex - 1</code>. Thus the length of the
	 * substring is <code>endIndex-beginIndex</code>. This behavior is like
	 * <code>String.substring(beginIndex, endIndex)</code>. Unicode escape
	 * sequences are not translated.
	 * 
	 * @param beginIndex
	 *            the beginning index, inclusive.
	 * @param endIndex
	 *            the ending index, exclusive.
	 * @throws IndexOutOfBounds
	 *             if either offset is outside of the array bounds
	 */
	char[] getRawCharacters(int beginIndex, int endIndex);

	/**
	 * Return the name of an identifier or token for the current token.
	 */
	Name name();

	/**
	 * Read token.
	 */
	void nextToken();

	/**
	 * Return the current token's position: a 0-based offset from beginning of
	 * the raw input stream (before unicode translation)
	 */
	int pos();

	/**
	 * Return the last character position of the previous token.
	 */
	int prevEndPos();

	/**
	 * Return the radix of a numeric literal token.
	 */
	int radix();

	/**
	 * The value of a literal token, recorded as a string. For integers, leading
	 * 0x and 'l' suffixes are suppressed.
	 */
	String stringVal();

	/**
	 * Return the current token, set by nextToken().
	 */
	Token token();

	/**
	 * Sets the current token.
	 */
	void token(Token token);
}
